296 WINDOW GARDENING. [CHAP. XI. 



because there are only two made out of a cast ; 

 and the smallest-numbered size, which is only- 

 two inches in diameter, is called a sixty, be- 

 cause there are sixty pots made out of one cast. 

 When I was in my gardening noviciate, I used 

 to be very much puzzled when I was told that 

 rooted cuttings should be potted in thumbs or 

 in sixties, and that a plant which required trans- 

 planting should be put in a twelve or an eight. 

 Thumbs are still smaller pots than sixties, for 

 there are eighty to the cast ; but they are not 

 described by their number, and are called thumb- 

 pots, because they will not hold more than a 

 large-sized thumb. Besides the common flower- 

 pots, there are double pots, one of which has 

 been sent me by Captain Mangles, which are 

 very useful for balconies, as the roots of the 

 plants are apt to be injured by the outside of 

 the pot in which they grow being dried by the 

 wind, or heated by the sun. When double pots 

 are used, the interstice between the pots may 

 be stuffed with moss kept moist. It does not 

 do, however, to keep plants long in these pots 

 without changing the moss, as if it is suffered 

 to cake together, it prevents the air from enter- 

 ing through the pores of the flower-pot, which 

 it should do to keep the roots in a healthy state. 

 China or any kind of glazed pots may also 

 be used for balconies, as the material of which 

 they are composed does not permit evaporation ; 

 but they are liable to the same objection as pots 

 glazed inside, though in a less degree, and when 

 used they should always be filled at least a third 

 of their depth with broken crocks, or potsherds, 

 to insure drainage. A very elegant Etruscan 



